Adjustable operating mechanism for brakes, clutches, and the like



Oct. 21, 1958 c. H. HESS 2,856,792

ADJUSTABLE OPERATING MECHANISM FOR BRAKES, CLUTCHES. AND THE LIKE Filed Jan. 51, 1955 r 2 Sheets-Sheet 1 IN VENTOR.

61H HE SS ADJUSTABLE OPERATING MECHANISM FOR BRAKES, CLUTCHES. AND THE LIKE Filed Jan. 51, 1955 Y 2 Sheets-Sheet 2 Oct. 21, 1958 c H HESS 2,856,792

IN VEN TOR.

C H. HE S 5 United States Patent O ADJUSTABLE OPERATING MECHANISM FOR BRAKES, CLUTCHES, AND THE LIKE Application January 31, 1955, Serial No. 484,984

3 Claims. (Cl. 74-520) This invention relates to operating mechanism and more particularly to adjustable operating mechanism for use in the actuation of automotive mechanism such as clutches, brakes, and the like.

In mechanisms of the general character noted above, it is known to be conventional to use toggles for exerting the necessary forces to accomplish changes in positions of one or more of the movable parts of the mechanism. Because of wear and the like in the parts, a toggle mechanism adequate in the operation of the mechanism when new, loses its efiiciency as the mechanism becomes older and wears. Of course the toggle mechanism may be adjusted to compensate for wear, but in most instances this requires substantial disassembly of the structure so that access can be had to the adjustment. which the adjustment is available from the outside of the assembly, the internal phases of the adjustment are so complicated asto render them inadequate from the standpoint of economy and efiiciency.

According to the present invention, these disadvantages are overcome by the use of what may be termed a double toggle mechanism, one of which is changed by an operating lever to achieve movement of a movable part away from and back to a starting position, the second toggle mechanism being unaffected except as it is movable bodily upon actuation of the first toggle mechanism. However, the second toggle may be adjusted independently of actuation of the first toggle mechanism for compensating for wear in the parts. The adjustment of the toggle features the use of an externally available adjusting member. The range of movement of the adjustment as elfecting changes in the position or angularity of the second toggle is materially increased by the use of coaxial, dual-threaded adjusting members, the members respectively having threads of opposite hand, whereby the members move in the same axial direction but relative to each other to accomplish adjustment without undue projection of one of the members externally of the housing in which the adjustable parts are carried.

The foregoing and other important objects and desirable features inherent in and encompassed by the invention will become apparent as a preferred .embodiment of the invention is disclosed in detail in the following specification and accompanying sheets of drawings, the several figures of which will be described immediately below.

Fig. l is a fragmentary side elevational view, with certain internal parts exposed, and representing one form of driving or operating mechanism in which the improved structure is usable.

Fig. 2 is a fragmentary sectional view on an enlarged scale as seen along the line 22 of Fig. 1.

Fig. 3 is an enlarged sectional view as seen along the line 3-3 of Fig. 1.

Fig. 4 is a sectional view of that portion of the structure designated by the encircled'numeral 4 in Fig. 1.

Fig. 5 is a fragmentary view of that portionof the structure designated by the encircled numeral 5 in Fig. 1.

In those cases in Fig. 6 is an enlarged sectional view as seen along the line 6-6 of Fig. 1.

Fig. 7 is an enlarged fragmentary view, on an enlarged scale, of the left-hand portion of the structure shown in Fig. 1, showing the parts in their normal or starting positions.

Fig. 8 is a similar view but showing the parts in their operative positions.

Fig. 9 is a similar view, showing the parts in their operative positions after maximum adjustment has been made by the adjusting means.

The operating mechanism chosen for purposes of illustration represents part of the driving mechanism of an agricultural tractor. A support is afforded by a housing 10, and within this support is journaled a shaft 12 on which is mounted a planetary gear train, designated generally by the numeral 14. The details of the planetary gear train are not essential to an understanding of the present invention and for that purpose there have been illustrated only :a pair of planetary ring gears or drums 16 and 18, the suggested association of which with other parts of the planetary gear train will be apparent from the illustration of internal teeth at 20 and 22, respectively.

The desideratum in the operation of the presently illustrated planetary gear train is the selective braking and release of the ring gears or drums 16 and 18. For this purpose, the drums are respectively toothed or splined as at 24 and 26 to respectively carry brake rings 28 and 30. The sets of brake rings 28 and 30 are separated by a central fixed ring 32 and a pair of separately and relatively movable actuating rings 34 and 36, the entire assembly being sandwiched between inner and outer fixed rings 38 and 40. The fixed rings 38 and 40 are rigidly secured together as by cap screws 42 (Fig. 2), and the outer ring 40 is secured at circumferentially spaced portions thereof by cap screws 44 to the support or housing 10. i

In a neutral operating position of the planetary gear train 14, the drums or ring gears 16 and 18 are free to rotate. Diiierent speed ratios are accomplished by braking one or the other of the drums. As best seen in Fig. 2, selected braking is accomplished by rotating either of the movable rings 34 or 36 relative to the fixed rings 32, 38, and 40, depending upon which drum is to be braked. The ring 34 is separated from the fixed central ring 32 by a plurality of balls 46 and a similar set of balls 48 is disposed between the other side of the ring 32 and the proximate face of the ring 36. The balls are received in normally alined conical pockets, which means that when the ring 34, for example, is moved angularly relative to the other rings, a wedging action occurs which forces the ring 34 axially against the associated set of brake rings 28 and squeezes these rings between the rings 34 and 38, thus braking the drum 16. A similar result will obtain upon actuation of the other ring 36.. For present purposes, the duality of the planetary gear set is without significance.

A plurality of short coil springs 50 cross-connects the rings 34 and 36 to tend to return the rings to their neutral positions in which the brake sets 28 and 30 are released (Fig. 5). In addition to the springs 50, other springs are provided for centering the rings or returning them to.

neutral. One such return spring is shown at 52in Figs. 1, 7, 8, and 9, the movable ring 36 having a lug 54 thereon to which the end of the spring 52 is connected. The other end of the spring is anchored to the housing or support 10.

According to the present invention, improved means is provided for actuating the rings 34 and 36. The rings as such may be assumed to be somewhat conventional and therefore either of the rings may be taken as representative of a movable part, the actuation of which will effectuate or mobilize operating mechanism such as a clutch or a brake. Since actuation of either of the rings 34 or 36 is the same, further reference will be had only to the control of the ring 36 as a movable part, capable ofmovement away from and'back to a normal starting position, which starting position, as willhereinafter ap'-'- pear, may be adjusted or changed. For the purpose of receiving forces necessary to elfect control of the movable part or ring 36, the ring has integral therewith a mounting lug 56 to which is connected operating structure best shown in Figs. 1, 6, 7, 8, and 9'and which will be described below.

The housing 'has an upper andre'arwardly disposed fixed or support part 58 in which a control lever 60 is mounted by means of a ball 62 tohave' universal movement. The lowerend of the lever 60; as at 64, is selectively engageable with any one of three actuators 66, 68, and 70', the actuators being pocketed or recessed, as best shownin Fig. 6, to receive the end of the lever 60. The arrangement issuch that only one of the actuators may be moved at any one time, each to the exclusion of any other. As already indicated, the present invention can be understood on the basis of an explanation of control of the ring 36 and therefore the following. description will be limited to the relationship between that ring and the actuator 66.

The actuator 66, like the other actuators, is mounted on a transverse rockshaft 72, which is appropriately journaled in the upper support part 58. This rockshaft provides a transverse axis for the pivotal mounting of an actuating. arm 74, which is here shown as being formed integral with the actuator 66. When the lever 60 is moved laterally because of its'ball mounting at 62, the lower end 64 thereof selects the actuator 66 and fore-andaft rocking of the lever then causes fore-and-aft rocking of the actuator 66 and its integral arm 74 about the axis afforded by the rockshaft 72. Figs. 1 and 7 show the neutral or normal position of the actuator 66, an adjustable stop 76 being provided to engage a boss 78 on the actuator for achieving this neutral position.

In the normal starting position of the ring 36 (Fig. 7), the lug 56 is a certain distance from the rockshaft 72. The purpose of the mechanism to be described below is to change this distance and thus to cause angular movement of the ring 36, resulting in squeezing of the set of brake rings 30 between the'ring 36 and its associated outer ring 40.

The arm 74-has a freeend connected on a first pivot 80 tothe first end of a first link or bell crank 82. The normal relationship between the arm 74 and the link or hell crank 8 2 is such as to aiford a first toggle 84. A second link 86 is pivotally connected at 88 to the lug 56 on the ring, 36 and its other or second end is connected on a second pivot 90 to an intermediate portion of the bell crank 82}. The relationship between the bell crank 82 and the link 86 is such as to alford a second toggle 92. Considered broadly as a simple link, the bell crank 82 will thus be seen to have first and second ends pivotally connectedat 80 and 90 respectively to the arm 74 and link 86. However, because of certain design considerations, the bell crank form is preferred to be used. Considered in this light, the bell crank has a second arm portion pivotally connected at 94 to another link 96 thatforr'ns part of anchor means, here designated generally by the numeral 98.

The anchor means is adjustable, as best shown in Fig. 4, wherein it will be seen that the support 10 has an integral hollow boss 100 bored at 102 to slidably receive a linearly movable member 104 and internally threaded at 106 to receive an externally threaded member 108. The member 108 projects exteriorly of the housing and carries a' jam nut 110 and is further provided with a squared portion 112 to receive a wrench or other forcetransmitting tool.

The externally threaded member 108 isinternally 4 threaded at 114 to receive an externally threaded extension 116 of the member 104. Since the housing 10 is adapted to contain lubricant, the member 104 has an annular groove within which is received an appropriate oil seal 118. The internal end of the member 104 is pivotally connected at 120 to the link 96.

The nature of the adjustment afforded at 98 is such that the member 1 04 may be heldin any selected fixed position and the-position may be changed by rotating the member 108 via the wrench-receiving end 112. Maximum adjustment within alimitedrange is accomplished because the threads at 106'108' and 1'14'116 are of opposite hand. These threads are further of difierent pitches. In the preferred construction illustrated, the threads at l06l08 are right-hand threads, fourteen per inch on a seven-eighths diameter; the threads at 114116 are lefthand and are sixteen per inch on a three-eighths diameter. Consequently, as the member 108 is rotated to withdraw it from the housing,the threads 11'4--1 16 cause a simultaneous but multiplied withdrawal of the member 104, the arrangement giving substantially twice the adjustment that would be possible were the member 108*us'ed alone.

Operation The starting, position of the movable part or ring 36' is represented in Figs; 1 and 7, wherein, as previously stated, there exists a certain distance between the" rockshaft' 72- and the lug 56 on the ring- 36. The arrangement of the toggle linkage is such that the distance between 72 and 56- is" increased when the controllever 68 is: rocked forwardly so as to cause the actuator 66 to move in a counterclockwise direction about the rockshaft 72-. Such movement causes forward and upward swinging of the pivot as effected between the free endof the arm 74 and the upper or first end of the link orbell crank 82. In other words, the first toggle 84' is straightened. This all assumes that there is no changein the adjusting means 98, which is consistent with the normal operation of the mechanism, because the ad'- justment at 98 is independent of operation of the toggle 84. Hence, in the interests of brevity and clarity, let it be assumed that the adjustment at 98 is fixed. Thus,

there is afforded a floating connection for the second pivot in the second toggle 92.. That is to say, the fixed adjustment at 98 constrains the toggle against changes that would afiect the distance between the rockshaft '72 and the lug. 56; but the arrangement permits bodily movement of thelinkage 82-86 in the directions of movement of the ring: 36. This result will best be seenby a: comparison of Figs.- 7 and 8, whereinit shows that there is no change inthe toggle 92 even though the toggle 84 is changed to such extent as to move past dead center, as determined by the relationship betweenv the axis of the rockshaft 72, the axis ofthe pivot 80, andthe axis of the pivot 88. The overcenter lock thus established keeps the brake applied on the drum or ring gear 13. When the control lever 60 is moved in the opposite direction, the overcenter lock is broken and neutral position is achieved by means of the return spring 52 and the return springs 50.

As long as no adjustment isefiected at 98, the ring.

36- moves away from and back to a starting position represented by Fig. 7. However, as the parts wear, the travel obtainable from straightening of the first toggle 84 may not be sufllcient to move the ring 36 enough to obtain the necessary braking action at 30-36 Upon such occasion, the adjustment at 98 becomes effective. As will be seen, this adjustment efiects, changes in the toggle 92. Specifically, in order to increase the distance between 80 and 88, the toggle 92' must be straightened, which is accomplished by rotation of the threaded member 108 so that it moves outwardly ofthe housing 10, as shown in Fig. 9. Straightening of the toggle at 92 is withoutefiect on the toggle at 84, so that,

once the adjustment is accomplished, control of the mechanism remains the same.

Briefly, what is accomplished here is the provision of the first and second toggles 84 and 92. The toggle 92 is normally unaffected, while the toggle 84 is changed to vary the distance between 72 and 56. However, and quite apart from changes in the toggle 84, changes may be effected in the toggle 92 to vary the distance between 80 and 56, which achieves a new starting position for the ring 36. That is to say, the starting position is farther in the direction of the ultimate or end position that should be obtained in order to secure the proper application of the brake at 30--36-40.

The other actuator is connected by similar toggle mechanism (not shown in detail) to the other brake ring 34. These, as will be apparent from the foregoing, are operative selectively and what has been said for one applies also to the other.

The central actuator 68 is connected by a link 122 to a bell crank 124 for the purposes of operating a trans mission brake 126, which brake is apart from those previously described and which is mentioned here only because of the illustration of the invention in conjunction with the plural-actuator system shown.

The maximum or overcenter position of the actuator 66 is established by engagement between a pair of stops, one of which is a boss 128 on the actuator and the other of which is an adjustable screw 130 carried by the support or housing 10.

Features of the invention not categorically enumerated will undoubtedly occur to those versed in the art, as will various modifications and alterations in the preferred embodiment of the invention illustrated, all of which may be achieved without departing from the spirit and scope of the invention.

What is claimed is:

1. Operating mechanism of the character described, comprising: a support; a movable part carried by the support for movement away from and back to a normal starting position; an arm having one end rockably carried on the support on an axis spaced a certain distance from the normal starting position of the movable part, said arm having a free end; a first operating link having a first end connected on a first pivot to the free end of the arm and combining with said arm to afford a first toggle, said first link having a second end proximate to the movable part; a second operating link having a first end connected to the movable part and further having a second end connected to the second end of the first link on a second pivot and affording a second toggle; anchor means on the support and connected to the second toggle at the sceond pivot for constraining the sectond toggle against changes therein while enabling bodily movement of the links in the directions of movement of the movable part; means for rocking the arm to change the first toggle and to act through the constrained sectond toggle to change the distance between the axis of the arm and the movable part; and said anchor means being adjustable on the support independently of rocking of the arm to selectively change the second toggle for varying the distance between the second pivot and the movable part whereby to change the starting position of the movable part.

2. The invention defined in claim 1, in which: the anchor means includes an anchor member carried by the support in offset relation to the path of movement of the operating links as they move bodily when the arm is rocked, and an anchor link connected at one end to one of the operating links to move therewith as aforesaid and pivoted at its other end on the anchor member for swinging relative to said anchor member.

3. Operating mechanism of the character described,

comprising: a support; a movable part carried by the support for movement away from and back to a normal starting position; an arm having one end rockably carried on the support on an axis spaced a certain distance from the normal starting position of the movable part, said arm having a free end; a bell crank having a first end connected on a first pivot to the free end of the arm and combining with said arm to afford a first toggle, said bell crank having an intermediate portion adjacent to the movable part and a second end projecting toward the support; a link having a first end connected to the movable part and a second end connected to the intermediate portion of the bell crank on a second pivot and affording a second toggle; an anchor member carried by the support for selective adjustment among a plurality of fixed positions and connected to the second end of the bell crank for constraining the second toggle against changes in any of said fixed positions but adjustable to change said second toggle to produce new starting positions for the movable part; and means for rocking the arm to change the first toggle and to act through the selected constrained second toggle for moving the movable part from any selected starting position.

References Cited in the file of this patent UNITED STATES PATENTS 465,536 Robinson Dec. 22, 1891 993,916 Vogel May 30, 1911 1,163,345 Isbell Dec. 7, 1915 2,269,308 Gates Jan. 6, 1942 FOREIGN PATENTS 10,661 Great Britain Feb. 29, 1912 370,191 Germany Feb. 28, 1923 858,385 France May 13, 1940 

